#1) I agree that quant's tip is useful. In this method, it seems background color information is stored in each info item as a file, which is independent of UR template. I mean background color information is NOT an attribute of UR info item.

#2) Still I think mikeg's suggestion to attach attributes to templates indicates different direction to pursue. This must be useful and is different from method #1.

#3) I also want to change background color as a setting of UR's internal editor. I don't want to change Windows' system-wide window setting since this take effects on every other app in Windows. What I want is just change the default background color of UR's editor.

In these three methods, the place which holds background color information is different. In a file(#1), in an attribute(#2), or in a UR editor settings(#3). There must be priority order among these. I think the natural order is #1 > #2 > #3 which means , for example, #1 overwrites #2 and/or #3.